procutil: make stream detection in make_line_buffered more correct and strict
In make_line_buffered(), we don’t want to wrap the stream if we know that lines
get flushed to the underlying raw stream already.
Previously, the heuristic was too optimistic. It assumed that any stream which
is not an instance of io.BufferedIOBase doesn’t need wrapping. However, there
are buffered streams that aren’t instances of io.BufferedIOBase, like
Mercurial’s own winstdout.
The new logic is different in two ways:
First, only for the check, if unwraps any combination of WriteAllWrapper and
winstdout.
Second, it skips wrapping the stream only if it is an instance of io.RawIOBase
(or already wrapped). If it is an instance of io.BufferedIOBase, it gets
wrapped. In any other case, the function raises an exception. This ensures
that, if an unknown stream is passed or we add another wrapper in the future,
we don’t wrap the stream if it’s already line buffered or not wrap the stream
if it’s not line buffered. In fact, this was already helpful during development
of this change. Without it, I possibly would have forgot that WriteAllWrapper
needs to be ignored for the check, leading to unnecessary wrapping if stdout is
unbuffered.
The alternative would have been to always wrap unknown streams. However, I
don’t think that anyone would benefit from being less strict. We can expect
streams from the standard library to be subclassing either io.RawIOBase or
io.BufferedIOBase, so running Mercurial in the standard way should not regress
by this change. Py2exe might replace sys.stdout and sys.stderr, but that
currently breaks Mercurial anyway and also these streams don’t claim to be
interactive, so this function is not called for them.
Test EOL patching
$ cat >> $HGRCPATH <<EOF
> [diff]
> git = 1
> EOF
Set up helpers
$ seteol () {
> if [ $1 = "LF" ]; then
> EOL='\n'
> else
> EOL='\r\n'
> fi
> }
$ makerepo () {
> seteol $1
> echo
> echo "# ==== setup $1 repository ===="
> echo '% hg init'
> hg init repo
> cd repo
> cat > .hgeol <<EOF
> [repository]
> native = $1
> [patterns]
> unix.txt = LF
> win.txt = CRLF
> **.txt = native
> EOF
> printf "first\r\nsecond\r\nthird\r\n" > win.txt
> printf "first\nsecond\nthird\n" > unix.txt
> printf "first${EOL}second${EOL}third${EOL}" > native.txt
> hg commit --addremove -m 'checkin'
> cd ..
> }
$ dotest () {
> seteol $1
> echo
> echo "% hg clone repo repo-$1"
> hg clone --noupdate repo repo-$1
> cd repo-$1
> cat > .hg/hgrc <<EOF
> [extensions]
> eol =
> [eol]
> native = $1
> EOF
> hg update
> echo '% native.txt'
> cat native.txt
> echo '% unix.txt'
> cat unix.txt
> echo '% win.txt'
> cat win.txt
> printf "first${EOL}third${EOL}" > native.txt
> printf "first\r\nthird\r\n" > win.txt
> printf "first\nthird\n" > unix.txt
> echo '% hg diff'
> hg diff > p
> cat p
> echo '% hg revert'
> hg revert --all
> echo '% hg import'
> hg import -m 'patch' p
> echo '% native.txt'
> cat native.txt
> echo '% unix.txt'
> cat unix.txt
> echo '% win.txt'
> cat win.txt
> echo '% hg diff -c tip'
> hg diff -c tip
> cd ..
> rm -r repo-$1
> }
Run tests
$ makerepo LF
# ==== setup LF repository ====
% hg init
adding .hgeol
adding native.txt
adding unix.txt
adding win.txt
$ dotest LF
% hg clone repo repo-LF
4 files updated, 0 files merged, 0 files removed, 0 files unresolved
% native.txt
first
second
third
% unix.txt
first
second
third
% win.txt
first\r (esc)
second\r (esc)
third\r (esc)
% hg diff
diff --git a/native.txt b/native.txt
--- a/native.txt
+++ b/native.txt
@@ -1,3 +1,2 @@
first
-second
third
diff --git a/unix.txt b/unix.txt
--- a/unix.txt
+++ b/unix.txt
@@ -1,3 +1,2 @@
first
-second
third
diff --git a/win.txt b/win.txt
--- a/win.txt
+++ b/win.txt
@@ -1,3 +1,2 @@
first\r (esc)
-second\r (esc)
third\r (esc)
% hg revert
reverting native.txt
reverting unix.txt
reverting win.txt
% hg import
applying p
% native.txt
first
third
% unix.txt
first
third
% win.txt
first\r (esc)
third\r (esc)
% hg diff -c tip
diff --git a/native.txt b/native.txt
--- a/native.txt
+++ b/native.txt
@@ -1,3 +1,2 @@
first
-second
third
diff --git a/unix.txt b/unix.txt
--- a/unix.txt
+++ b/unix.txt
@@ -1,3 +1,2 @@
first
-second
third
diff --git a/win.txt b/win.txt
--- a/win.txt
+++ b/win.txt
@@ -1,3 +1,2 @@
first\r (esc)
-second\r (esc)
third\r (esc)
$ dotest CRLF
% hg clone repo repo-CRLF
4 files updated, 0 files merged, 0 files removed, 0 files unresolved
% native.txt
first\r (esc)
second\r (esc)
third\r (esc)
% unix.txt
first
second
third
% win.txt
first\r (esc)
second\r (esc)
third\r (esc)
% hg diff
diff --git a/native.txt b/native.txt
--- a/native.txt
+++ b/native.txt
@@ -1,3 +1,2 @@
first
-second
third
diff --git a/unix.txt b/unix.txt
--- a/unix.txt
+++ b/unix.txt
@@ -1,3 +1,2 @@
first
-second
third
diff --git a/win.txt b/win.txt
--- a/win.txt
+++ b/win.txt
@@ -1,3 +1,2 @@
first\r (esc)
-second\r (esc)
third\r (esc)
% hg revert
reverting native.txt
reverting unix.txt
reverting win.txt
% hg import
applying p
% native.txt
first\r (esc)
third\r (esc)
% unix.txt
first
third
% win.txt
first\r (esc)
third\r (esc)
% hg diff -c tip
diff --git a/native.txt b/native.txt
--- a/native.txt
+++ b/native.txt
@@ -1,3 +1,2 @@
first
-second
third
diff --git a/unix.txt b/unix.txt
--- a/unix.txt
+++ b/unix.txt
@@ -1,3 +1,2 @@
first
-second
third
diff --git a/win.txt b/win.txt
--- a/win.txt
+++ b/win.txt
@@ -1,3 +1,2 @@
first\r (esc)
-second\r (esc)
third\r (esc)
$ rm -r repo
$ makerepo CRLF
# ==== setup CRLF repository ====
% hg init
adding .hgeol
adding native.txt
adding unix.txt
adding win.txt
$ dotest LF
% hg clone repo repo-LF
4 files updated, 0 files merged, 0 files removed, 0 files unresolved
% native.txt
first
second
third
% unix.txt
first
second
third
% win.txt
first\r (esc)
second\r (esc)
third\r (esc)
% hg diff
diff --git a/native.txt b/native.txt
--- a/native.txt
+++ b/native.txt
@@ -1,3 +1,2 @@
first\r (esc)
-second\r (esc)
third\r (esc)
diff --git a/unix.txt b/unix.txt
--- a/unix.txt
+++ b/unix.txt
@@ -1,3 +1,2 @@
first
-second
third
diff --git a/win.txt b/win.txt
--- a/win.txt
+++ b/win.txt
@@ -1,3 +1,2 @@
first\r (esc)
-second\r (esc)
third\r (esc)
% hg revert
reverting native.txt
reverting unix.txt
reverting win.txt
% hg import
applying p
% native.txt
first
third
% unix.txt
first
third
% win.txt
first\r (esc)
third\r (esc)
% hg diff -c tip
diff --git a/native.txt b/native.txt
--- a/native.txt
+++ b/native.txt
@@ -1,3 +1,2 @@
first\r (esc)
-second\r (esc)
third\r (esc)
diff --git a/unix.txt b/unix.txt
--- a/unix.txt
+++ b/unix.txt
@@ -1,3 +1,2 @@
first
-second
third
diff --git a/win.txt b/win.txt
--- a/win.txt
+++ b/win.txt
@@ -1,3 +1,2 @@
first\r (esc)
-second\r (esc)
third\r (esc)
$ dotest CRLF
% hg clone repo repo-CRLF
4 files updated, 0 files merged, 0 files removed, 0 files unresolved
% native.txt
first\r (esc)
second\r (esc)
third\r (esc)
% unix.txt
first
second
third
% win.txt
first\r (esc)
second\r (esc)
third\r (esc)
% hg diff
diff --git a/native.txt b/native.txt
--- a/native.txt
+++ b/native.txt
@@ -1,3 +1,2 @@
first\r (esc)
-second\r (esc)
third\r (esc)
diff --git a/unix.txt b/unix.txt
--- a/unix.txt
+++ b/unix.txt
@@ -1,3 +1,2 @@
first
-second
third
diff --git a/win.txt b/win.txt
--- a/win.txt
+++ b/win.txt
@@ -1,3 +1,2 @@
first\r (esc)
-second\r (esc)
third\r (esc)
% hg revert
reverting native.txt
reverting unix.txt
reverting win.txt
% hg import
applying p
% native.txt
first\r (esc)
third\r (esc)
% unix.txt
first
third
% win.txt
first\r (esc)
third\r (esc)
% hg diff -c tip
diff --git a/native.txt b/native.txt
--- a/native.txt
+++ b/native.txt
@@ -1,3 +1,2 @@
first\r (esc)
-second\r (esc)
third\r (esc)
diff --git a/unix.txt b/unix.txt
--- a/unix.txt
+++ b/unix.txt
@@ -1,3 +1,2 @@
first
-second
third
diff --git a/win.txt b/win.txt
--- a/win.txt
+++ b/win.txt
@@ -1,3 +1,2 @@
first\r (esc)
-second\r (esc)
third\r (esc)
$ rm -r repo